Capital Equipment News December 2018

• Diesel engines have jumped from 35% efficiency in the 1980s to 50% now • A gasoline engine is around 35 % efficient • The best power stations operate at 50-55% efficiency

will form part of the future combustion driveline solution.

Dr. Staffan Lundgren is a lead strategist at the Volvo Group, specialising in evaluating new technologies for the future of propulsion.

Q: Can other technology help lower fuel bills? SL: Examples are stop/start technology and 48 V electric systems that power ancillaries electrically, rather than mechanically. These may all have future uses in heavy duty applications, once their robustness is proven. But another important source of greater efficiency is heat recovery. This is not an easy task on heavy duty engines, as they run relatively cold exhausts, but there is still hope to capture it and make it commercially viable. Q: What is the maximum efficiency an engine can achieve? SL: The diesel engine has a theoretical system efficiency of between 55-60%. For reference, the best power stations operate at 50-55% efficiency, and fuel cells are also around 50%+ efficient – so diesel engines can be incredibly efficient. This, added to the fact that engines working with electrification will often have a lower power demand, will mean fuel use is set to decline in the future. Q: How long can the diesel engine survive? SL: The diesel combustion engine remains a very cost-efficient solution for creating mechanical energy. That said, legislation, especially in Europe, is pushing towards electrification quite strongly, and that may impact directly on the combustion engine’s longevity. Our feeling is that its use will be application-based, and that it will continue for a considerable time in long distance uses, such as ocean-going ships and long-haul trucks. But even here there will probably be a blend of technologies in use. Q: Is diesel part of the future? SL: The diesel engine – in a modified form – can be very clean and efficient. It also plays well with electrification. As a manufacturer we need to find the best solution, based on the decisions society makes. Whatever they are, we need to be prepared. b

Q: The diesel engine is accused of being environmentally unfriendly. Can it clean up its act? SL: Making diesel engines very clean is possible and that is something that the heavy duty industry has made greater progress on than the light duty sector. Part of the reason for this is that the efficiency demanded by customers in the heavy duty sector is much higher. Q: How hard has it been to increase efficiency while at the same time lowering emissions? SL: It has been a challenge to refine the thermodynamic process to compensate for the burden of having added the SCR after- treatment system. But now we are back on track to increase efficiency step by step. Q: How much further can you go – zero emissions? SL: It depends on what you mean by emissions. If you propel the engine with fuel that has no carbon and couple it with an efficient combustion process that creates no soot, then zero emissions is possible. We have been working on using methane and DME (dimethyl ether) as clean alternatives to diesel. This is not a new idea, in 1900 the diesel engine was successfully run on peanut oil. The problem isn’t with the technology of making the clean fuels work, but rather their availability. But if the supply issue of renewable fuels can be solved, then it is

possible for diesel engines to run 100% CO 2 free.

Q: Don’t clean fuels also have their own environmental challenges? SL: Bio-fuel production shouldn’t compete with food production – but there are other fuels where this isn’t a problem. Electro- fuels (E-fuels) use solar or wind power to ‘crack’ water and combine it with CO 2 from methane – and these fuels feature quite high efficiency – up to 80% claimed. This could be an interesting complement to electrification. SL: From an efficiency point of view the engine doesn’t care if the fuel molecule comes from a fossil or a renewable source. So with investment in the right type of renewable fuels, the transition to renewables should be straightforward. SL: The next big step in increasing engine efficiency/lowering fuel consumption is its combination with electromobility. The demand on engines in the future will not be so varied as it is today. There is a difference between how efficient an engine is at its ‘sweet spot’ and how efficient across the whole real-world operating range. Partnering engines with electric motors, as in parallel hybrids, allows the engine to run at its most efficient level. Without doubt, electrification Q: How do different fuels affect the combustion? Q: So how do we lower fuel consumption further?

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